help modifying my Phono-stage

murphythecat8 · 11th July 2011, 11:18 PM

I'm totally newbie, this will be my first mod ever. This is the inside of the phono stage:Google Image Result for http://www.ippinkan.com/musical_fidelity/v-series/V-LPS_circuit800.jpg

Okay, I willl concentrate my effort for now on:

Swapping the powersupply
changing the fist stage op-amps and the second stage
changing all the caps to panasonic FC

I have a couple of question:

-I see three IC: IC1 (5532dd jrc 0024b), ic 301(NE5534AP) and IC 201 (NE5534AP). Which is which; IC1 is the second stage and IC301 and IC201 is the first stage? or is it the contrary? Should I need to replace all three with LME49710? Also I heard that the LME49710 is a good op-amp, but feel free to suggest me something that would probably be better.

-I need to replace all the caps. All the black one are jamicon and I change ALL of them? to panasonic FC, all with the same value, or I match the same value?
I seems to have 2 different jamicon caps: 100 uf 16V so I replace those with those:Wholesale taobao Panasonic FC 100UF/16V high-speed low-impedance capacitor
and the 16V 1000uf with those Panasonic FC 1000uF 16V :: Panasonic FC :: Panasonic :: Electrolytics :: Capacitors :: Passive Components :: Electronic Parts :: Banzai Music

Also, can I use something better then those panasonic ones, I could pay much more if I ccan see a difference...

nigelwright7557 · 12th July 2011, 12:35 AM

If it is of any age then the electrolytics will need changing.

Care needs to be taken with faster op-amps as you could end up with instability.

murphythecat8 · 12th July 2011, 01:16 PM

Quote:

Originally Posted by nigelwright7557

If it is of any age then the electrolytics will need changing.

Care needs to be taken with faster op-amps as you could end up with instability.

hi, the musical fidelity v-lps is brand new...

Leon08 · 12th July 2011, 01:39 PM

Quote:

I see three IC: IC1 (5532dd jrc 0024b), ic 301(NE5534AP) and IC 201 (NE5534AP). Which is which; IC1 is the second stage and IC301 and IC201 is the first stage? or is it the contrary?

It's hard to say without the schematic.But if there is a NE5534AP then I would be carefull with replacing it because it's not fully internally compensated and probably uses some additional compensation.So if you replace it with another opamp then it will be overcompensated.

murphythecat8 · 12th July 2011, 03:31 PM

Quote:

Originally Posted by Leon08

It's hard to say without the schematic.But if there is a NE5534AP then I would be carefull with replacing it because it's not fully internally compensated and probably uses some additional compensation.So if you replace it with another opamp then it will be overcompensated.

okay so I guess that the two ne5534ap are the first opamp stages. I will change the second stage op-amp

Leon08 · 12th July 2011, 06:17 PM

I see there 5 IC. 4 are for the phono stage and the fifth probably for power supply.What brand are IC 202 and 302? I assume they are also NE5534.

murphythecat8 · 12th July 2011, 07:50 PM

Quote:

Originally Posted by Leon08

I see there 5 IC. 4 are for the phono stage and the fifth probably for power supply.What brand are IC 202 and 302? I assume they are also NE5534.

yes, ic 202 and 302 are ne5534... I guess those don't afffect the sound and shouldn't be changed?

Frank Berry · 12th July 2011, 08:05 PM

Is there a reason why you are making the mods?
Are you unhappy with the sound of the preamp?
What are you trying to accomplish?

Leon08 · 12th July 2011, 08:41 PM

Quote:

yes, ic 202 and 302 are ne5534... I guess those don't afffect the sound and shouldn't be changed?

They are the second stage of the phono preamp and do affect the sound as well.

murphythecat8 · 09:42 PM

Quote:

Originally Posted by Leon08

They are the second stage of the phono preamp and do affect the sound as well.

okay, and with what do you propose to swap them?

which op-amp?

11th July 2011, 11:18 PM	#1
murphythecat8 diyAudio Member Join Date: Mar 2011	help modifying my Phono-stage I'm totally newbie, this will be my first mod ever. This is the inside of the phono stage:Google Image Result for http://www.ippinkan.com/musical_fidelity/v-series/V-LPS_circuit800.jpg Okay, I willl concentrate my effort for now on: Swapping the powersupply changing the fist stage op-amps and the second stage changing all the caps to panasonic FC I have a couple of question: -I see three IC: IC1 (5532dd jrc 0024b), ic 301(NE5534AP) and IC 201 (NE5534AP). Which is which; IC1 is the second stage and IC301 and IC201 is the first stage? or is it the contrary? Should I need to replace all three with LME49710? Also I heard that the LME49710 is a good op-amp, but feel free to suggest me something that would probably be better. -I need to replace all the caps. All the black one are jamicon and I change ALL of them? to panasonic FC, all with the same value, or I match the same value? I seems to have 2 different jamicon caps: 100 uf 16V so I replace those with those:Wholesale taobao Panasonic FC 100UF/16V high-speed low-impedance capacitor and the 16V 1000uf with those Panasonic FC 1000uF 16V :: Panasonic FC :: Panasonic :: Electrolytics :: Capacitors :: Passive Components :: Electronic Parts :: Banzai Music Also, can I use something better then those panasonic ones, I could pay much more if I ccan see a difference...

12th July 2011, 12:35 AM	#2
nigelwright7557 diyAudio Member Join Date: Apr 2008 Location: Carlisle, England	If it is of any age then the electrolytics will need changing. Care needs to be taken with faster op-amps as you could end up with instability. __________________ http://www.murtonpikesystems.co.uk PCBCAD40 pcb design software.

12th July 2011, 08:05 PM	#8
Frank Berry diyAudio Member Join Date: Sep 2003 Location: Midland, Michigan	Is there a reason why you are making the mods? Are you unhappy with the sound of the preamp? What are you trying to accomplish? __________________ Frank

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12th July 2011, 06:17 PM	#6
Leon08 Banned Join Date: Sep 2010 Location: at Home	I see there 5 IC. 4 are for the phono stage and the fifth probably for power supply.What brand are IC 202 and 302? I assume they are also NE5534.

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